Technical Field
The present disclosure relates to an integrated electronic device including a temperature transducer.
Description of the Related Art
As is known, there currently exist integrated electronic devices that each include an electronic component and at least one temperature transducer, which enables detection of the temperature in a point of the integrated electronic device. In this way, during use of the electronic component it is possible to determine whether it is necessary to implement strategies that will prevent damage to the integrated electronic device.
For instance, illustrated in FIG. 1 are a temperature transducer 1 and an electronic component 3, which form an integrated electronic device 6; for example, the electronic component 3 is a power MOSFET.
The temperature transducer 1 includes a diode 2, which is formed within a die 5, formed inside which is the integrated electronic device 6.
The diode 2 may be of polysilicon. For instance, as illustrated in FIG. 2, the die 5 includes an epitaxial region 8, for example of an N type, extending on which is a body region 10, for example of a P type. Extending on the body region 10 is a dielectric region 12, made, for example, of thermal oxide. This having been said, the diode 2 is formed by an anode region 16, made precisely of polysilicon and with doping of a P+ type, and a cathode region 18, of polysilicon and with doping of an N+ type. The anode region 16 and the cathode region 18 extend on the dielectric region 12. A top region 20, made, for example, of a phosphosilicate glass, extends on the dielectric region 12 and part of the diode 2. An anode metallization 22 and a cathode metallization 24 extend through the top region 20 for contacting the anode region 16 and the cathode region 18, respectively.
As illustrated in FIG. 1, the anode region 16 and the cathode region 18 are electrically connected, respectively, to a first pad 30 and a second pad 32 of conductive material. Furthermore, the diode 2 is arranged within the active area 37 of the electronic component 3, i.e., in a central area of the die 5. By way of example, FIG. 1 further shows a so-called gate pad 41 of the electronic component 3, as well as the so-called “gate fingers” 43. Further, the electrical connections between the diode 2 and the first and second pads 30, 32 are illustrated qualitatively.
In use, the first and second pads 30, 32 are electrically connected to a controller (not illustrated) designed to inject a current I into the first pad 30. The controller is thus designed to forward bias the diode 2. Further, the controller collects the current I on the second pad 32. In addition, albeit not illustrated, the controller is electrically coupled to the diode 2 so as to detect a voltage VF1 across the diode 2. Assuming that the diode 2 operates in the proximity of its threshold voltage, the voltage VF1 decreases approximately by 2 mV per degree centigrade.
Since the voltage VF1 depends upon the temperature of the diode 2, the controller may detect onset of situations that are potentially dangerous for operation of the integrated electronic device 6, on the basis of the voltage VF1. In particular, assuming, for example, that the integrated electronic device 6 is short-circuited, there occurs a fast increase in temperature of the diode 2, which may be detected by the controller, on the basis of the voltage VF1. Once an anomalous condition of use of the electronic component 3 has been detected, the controller may co-operate with the driving circuit (not illustrated) of the electronic component 3 in order to implement a technique of protection of the electronic component 3; for example, it is possible for the electronic component 3 to be turned off.
In this connection, FIG. 3 shows some examples of plots of the forward voltage across the diode 2, as the temperature varies, on the hypothesis of injection into the diode 2 of three different values of forward current. Further illustrated in FIG. 3 are a temperature threshold, an allowed operating region and a forbidden operating region for one of the three values of forward current.
In practice, the temperature transducer 1 transduces a temperature into a voltage to enable monitoring of the temperature. However, the temperature transducer 1 requires two additional pads with respect to the pads necessary for driving the electronic component 3. Consequently, the temperature transducer 1 entails a certain consumption of area of the die 5.